Many people have to use Di when collaborating on a project. Otherwise, there will be too much duplicate code. However, although this Di technology is absolutely necessary, it is difficult to learn unless you are in the field. However, this lecture will teach you various things from whether Di is good to how to use it, and will also guide you on methods that can be used in the field. You don't have to use it exactly as in the lecture, but it is worth listening to it once. If you learn Di conceptually, it will be of great help in your future development. You should definitely use it in the field.